1. Technical Field
The present invention relates to wrench-free devices for holding a tool or workpiece on a collet chuck of a rotating turbine and, more particularly, to a wrench-free manual chuck that can be changed quickly and easily.
2. Prior Art
Chucks have commonly been used in machine tools, drills and the like where a workpiece or tool must be grasped and held firmly in place. Unfortunately, conventional jaw chucks have a tendency to loosen their grip at high rotational speeds due to centrifugal force. To combat this tendency, collet chucks are often used. Collet chucks are typically more accurate and have a greater grasping characteristics than typical jaw chucks because they are not affected by centrifugal force. The collet chuck acts as a collar around the workpiece or tool, eliminating any loosening of the grasp.
One problem encountered with collet chucks is that slight variations in the diameter of the workpiece or tool could cause the collet to position the workpiece differently. When and where a collet will grasp a work piece depends on the difference in diameter between the open collet and the diameter of the workpiece. Precise workpiece diameter is therefore required if the workpiece is to be positioned precisely and consistently in machining operations such as facing, side finishing or cutting to precise lengths. Another problem encountered with conventional collet chucks is that the chuck cannot be easily and quickly removed from the spindle. As a result, changing collet chucks can be time consuming and frustrating to users needing to change workpieces frequently, like dentists, for example.
Accordingly, a need remains for a manual chuck with the grasping strength of a collet chuck and the quick release features of a manual jaw chuck.